1. Field of the Invention
The present invention relates to an in-wall heater which is disposed by being embedded in a recess formed in a room wall.
2. Description of the Related Art
As an in-wall heater of this kind, there has hitherto been known an in-wall heater which comprises an outer case, a combustion housing which is provided within the outer case and in which a burner is built, a heat exchanger which is provided within the outer case so as to be positioned behind the combustion housing and causes combustion exhaust gas from the combustion housing to flow, an air intake opening and a blast opening each provided in the outer case, a warm air fan within the outer case which sucks in room air from the air intake opening and sends the air into the room from the blast opening via a section where the heat exchanger is disposed, control equipment which is disposed in a side space on one lateral side between the outer case and the combustion housing within the outer case, and an exhaust duct downstream of the heat exchanger which is disposed in a side space on the other lateral side between the outer case and the combustion housing within the outer case (refer to the Japanese Utility Model Laid-Open No. 5-37129, for example).
In a usual on-floor heater, generally, an air intake opening is provided in the back surface of an outer case. In an in-wall heater, however, the outer case enters into the recess in a room wall and, therefore, it is impossible to suck in room air from the back surface side of the outer case. Therefore, in the above-described conventional in-wall heater, a bottom plate portion of the outer case is raised from the floor surface, the air intake opening is provided in the bottom plate portion, and the warm air fan is disposed behind this air intake opening. And the room air is sucked into the warm air fan from the air intake opening via the space below the combustion housing and the room air is sent from the warm air fan into the blast opening to an upper part of the front surface of the outer case via the section where the heat exchanger is disposed behind the combustion housing and the space above the combustion housing.
A filter is mounted on the air intake opening in order to prevent the entry of dust into the outer case and it is necessary to clean the filter by periodically detaching the filter. If the air intake opening is provided in the bottom plate portion of the outer case as in the above-described conventional in-wall heater, it is troublesome to attach and detach the filter and maintainability worsens.
In order to solve this problem, there is also known an in-wall heater in which an air intake opening is provided in a front surface of an outer case in addition to a blast opening (refer to the Japanese Utility Model Publication No. 6-69602, for example). In this in-wall heater, however, a suction sound generated when room air is sucked in from the air intake opening is radiated forward directly from the front surface of the outer case and the noise becomes large. Incidentally, also when an air intake opening is provided in a bottom plate portion of the outer case, a suction sound echoes in a space between the bottom plate portion and the floor surface and this echo is radiated to the front side of the heater, generating a relatively large noise.
When control equipment and an exhaust duct are disposed respectively in a side space on one lateral side and in a side space on the other side within the outer case as with the heater described in the Japanese Utility Model Laid-Open No. 5-37129, there is a fear that the temperature of the control equipment may rise due to the heat from the combustion housing, causing heat loss of the control equipment and, at the same time, there is a fear that the temperature in the side space on the other side may rise due to the heat from the combustion housing and the heat from the exhaust duct, causing overheating of the room wall.
In view of the above points, the present invention has as its object the provision of an in-wall heater which can suppress an increase in noise due to a suction sound without impairing maintainability and can ensure also cooling performance in side spaces within an outer case.